Can't get ambient display to work at all?

So, I have a Nexus 6 just switched back to it from my Moto X 2014 I have been using. I was on a custom rom Chroma and that was working fine and great no issues with ambient display. I just bought a new Sonata and want to use android auto and I can't use it with a custom rom so I had to flash back to stock. However, now no matter what I can't get ambient display to work properly...I even downloaded the app ACdisplay to kind of mirror what the moto x did and that won't even work. Any ideas?